Learning Objectives

After this training, providers will be able to:

  1. Explain the steps of correctly performing an ECG
  2. Understand the logistics of obtaining an ECG
  3. Analyze the ECG tracing to identify missing leads, lead reversal, and common signal artifacts
  4. Troubleshoot common problems related to ECG acquisition
  5. Independently obtain a high quality ECG
  6. Teach learners how to perform a high quality ECG

ECG walkthrough for patients at Cincinnati Children’s

  1. Order ECG in Epic
  2. Obtain ECG machine from storage location on A6C, sign log at HUC desk
  3. Place electrodes (stickers) and connect leads (wires) – detailed instructions below
    • For infants you may need to cut electrode stickers in half to fit them across the torso
  4. Press power button to turn on ECG machine
  5. Load patient’s ECG order:
    • Press F1 “Patient Data”
    • Verify 2 patient identifiers (name, DOB, MRN, etc.)
    • Option 1:
      • Scan patient barcode
      • Select the appropriate order (if multiple orders listed)
    • Option 2 (if scanner is not working):
      • Press F6 “More” > F2 “Main Menu” > F6 “More” > F4 “Order Manager Interface” > F2 “Load Orders”
      • Input correct patient location, then press Enter
      • Highlight desired patient using Up/Down arrows, press Enter to select patient
      • Press F6 “Load Orders” > Order will load to the cart, and patient will be listed in Order Manager > Press F1 “Select” to highlight the patient > Press Enter > Press F2 “Continue” > Patient information will appear on the screen
    • Enter your Network ID into the “Performing Tech” field
    • Troubleshooting:
      • Check back of cart to make sure cords are connected
      • Check for green light on back of cart to verify internet connection
  6. Evaluate electronic ECG tracing. Troubleshoot problems.
  7. When satisfied with electronic tracing, press “ECG” button to capture
  8. If unhappy with captured tracing, press F2 “Cancel” to discard and try again
  9. When satisfied with captured tracing, press F1 “Continue” to print and electronically transmit ECG
  10. Disconnect leads, remove and discard electrodes
  11. Clean equipment
  12. Return ECG machine to A6C, sign log at HUC desk

Proper Lead Placement

Always double check electrode placements and lead connections

Precordial leads

  • V1 – 4th intercostal space, right sternal border
  • V2 – 4th intercostal space, left sternal border
  • V3 – Midway between V2 and V4
  • V4 – 5th intercostal space, left midclavicular line
  • V5 – Same horizontal line as V4, anterior axillary line
  • V6 – Same horizontal line as V4 and V5, midaxillary line
  • V3R – Midway between V1 and V4R
  • V4R – 5th intercostal space, R midclavicular line

Limb leads

Limb leads can be placed anywhere on the appropriate extremity, as long as they do not break the torso plane

  • RA – Upper right arm
  • LA – Upper left arm
  • LL – Upper left leg
  • RL – Upper right leg (ground electrode)


Limb lead reversal

  • RA-LA reversal > downward QRS in I
  • RA-RL reversal > Isoelectric (flat) signal in II, upright QRS in aVR, downward QRS in I
  • LA-LL reversal > Upright QRS in aVL, decreased voltage in aVF, downward QRS in III, larger P wave in I compared to II

Precordial lead misplacement/reversal

  • Poor/inappropriate R wave progression in precordial leads


  • Patient movement leading to baseline drift
  • Muscle tremor leading to noisy signal
  • 60-Hz electrical interference leading to oscillating noise in signal

Incorrect scale settings

  • Standard voltage (y-axis) is 10 mm/mV
    • Higher setting will amplify signal
    • Lower setting will dampen signal
  • Standard speed (x-axis) is 25 mm/sec
    • Higher setting will widen waveforms
    • Lower setting will compress waveforms

Electrode and lead issues that reduce ECG quality

  • Dry electrodes due to package being left open
  • Adhesive buildup on lead wires
  • Cracked or damaged lead wires

Additional Resources

Life in the Fastlane: ECG lead positioning

Life in the Fastlane: ECG Limb Lead Reversal